Structural and EPR studies of Cu(2+)ons in NaPO3 - Sb2O3 - CuO glasses

Autor(es)

Franco, Douglas F. ^[1] ; Carvajal, Eduar E. ^[2] ; Donoso, Jose Pedro ^[3] ; Silva, Mauricio A. P. ^[4] ; Sant'Ana, Antonio C. ^[4] ; Fares, Hssen ^[1] ; Magon, Claudio J. ^[3] ; Nalin, Marcelo ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, UNESP, Inst Quim Araraquara, POB 355, BR-14801970 Araraquara, SP - Brazil

^[2] Univ Fed Sao Carlos, Dept Fis, BR-13565905 Sao Carlos, SP - Brazil

^[3] Univ Sao Carlos, Inst Fis Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil

^[4] Univ Fed Juiz de Fora, Inst Ciencias Exatas, Dept Quim, BR-36036900 Juiz de Fora, MG - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Non-Crystalline Solids; v. 503, p. 169-175, JAN 15 2019.
• Citações Web of Science: 1

Resumo

In this work, glass compositions in the system NaPO3 - Sb2O3 - CuO (PSbCu) containing different concentrations of CuO and Sb2O3 were prepared through the melt - quenching methodology. Thermal, structural and optical properties of the PSbCu glasses were systematically studied by differential scanning calorimetry (DSC), X-ray powder diffraction (XRD) and Raman, UV-Visible and Photoluminescence (PL) spectroscopies, besides electron paramagnetic resonance (EPR) measurements. The DSC curves for all samples presented the glass transition phenomenon (T-g), while the XRD patterns showed the presence of an amorphous halo, which confirmed the glassy nature of all samples analyzed. UV-Vis spectra of the glasses showed a transparent window from 450 to 800 nm. The EPR signals intensities were investigated as a function of the copper concentration and Sb2O3 content in the (PySb0.5Cu) (20 <= y <= 80) and (PSb80xCu) (0.25 <= x <= 1.25) glasses. The EPR results showed that the increase of Sb2O3 concentration on the PySb0.5Cu glasses decreased the Cu2+ signals, which suggests the Sb3+ oxidizing to Sb5+, also transferring electrons to Cu2+ species to create the EPR a silent Cu+ specie. According to EPR parameters and PL spectra (excited at 380 nm) of PySb0.5Cu glasses, the ions Cu2+ ions were preferentially found in a distorted octahedral geometry, while Cu+ is in a square planar geometry according to the Jahn-Teller effect. (AU)

• Processo FAPESP: 13/07793-6 - CEPIV - Centro de Ensino, Pesquisa e Inovação em Vidros
• Beneficiário: Edgar Dutra Zanotto
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 16/16900-9 - Preparação de fibras de vidros óxidos de metal pesado com propriedades ópticas e magneto-ópticas
• Beneficiário: Douglas Faza Franco
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado